Image control method and image control device

The present invention relates to an image control method and an image control device.

In JP 2018-079202 A described below, a display device that, by displaying an arrow extending from the own lane to an adjacent lane in a road image representing the own lane and the adjacent lane, informs that a lane change from the own lane to the adjacent lane is to be performed by autonomous driving is described.

However, there are some cases that when the own vehicle is caused to perform a lane change by autonomous travel control, the own vehicle is caused to perform a lane change to a lane farther than an adjacent lane by successively performing multiple lane changes. In such a lane change, an image display in JP 2018-079202 A cannot inform a passenger of whether a lane change to an adjacent lane is finally performed or lane changes further continue before start of a lane change.

An object of the present invention is to provide an image display capable of informing whether a lane change to an adjacent lane is finally performed or lane changes further continue before start of a lane change by autonomous travel control.

According to an aspect of the present invention, there is provided an image control method causing a controller to execute processing including: generating a road image representing an own lane, the own lane being a lane in which an own vehicle travels, and one or more other lanes existing on at least one lateral side of the own lane and including at least an adjacent lane, the adjacent lane being adjacent to the own lane; generating a lane change image by, in a case where the own vehicle is caused to perform a lane change by autonomous travel control, when a target lane determined as a destination lane of a lane change is determined to be one of displayed other lanes, the displayed other lanes being the other lanes displayed in the road image, superimposing a first course display representing a course in which a lane change from the own lane to the target lane included in the displayed other lanes is performed on the road image and, when the target lane is determined to be none of the displayed other lanes, superimposing a second course display representing a course in which a lane change from the own lane to one of the displayed other lanes is performed and a lane change to an outer side of the displayed other lanes is further performed on the road image; and displaying the lane change image on a display device.

According to an aspect of the present invention, it is possible to provide an image display capable of informing whether a lane change to an adjacent lane is finally performed or lane changes further continue before start of a lane change by autonomous travel control.

The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention.

(Configuration)

1 FIG. 10 1 11 12 13 14 15 16 17 18 19 20 is a diagram illustrative of an example of a schematic configuration of a vehicle on which a driving assistance device of an embodiment is mounted. A driving assistance devicemounted on a vehicleincludes a sensor, a positioning device, a map database (map DB), an in-vehicle device, a navigation system, a display device, a sound output device, an input device, a vehicle behavior control device, and a controller. The above-described devices are connected to one another via, for example, a controller area network (CAN) or another in-vehicle LAN in order to perform transmission and reception of information with one another.

11 1 11 1 1 1 11 1 1 1 11 1 The sensordetects a travel state of the vehicle. For example, the sensorincludes cameras, such as a front view camera for capturing a front view of the vehicle, a rear view camera for capturing a rear view of the vehicle, and side view cameras for capturing right and left side views of the vehicle. In addition, the sensorincludes radars, such as a front radar for detecting an obstacle in front of the vehicle, a rear radar for detecting an obstacle in the rear of the vehicle, and side radars for detecting an obstacle existing on the right and left lateral sides of the vehicle. Further, the sensorincludes a vehicle speed sensor for detecting vehicle speed of the vehicle, a touch sensor (capacitance sensor) for detecting holding of a steering wheel by a passenger (for example, a driver), an in-vehicle camera for imaging the passenger, and the like.

12 12 1 12 1 1 The positioning deviceincludes a GPS unit, a gyro sensor, a vehicle speed sensor, and the like. The positioning devicedetects radio waves transmitted from a plurality of satellites by the GPS unit and periodically acquires position information of the vehicle. In addition, the positioning devicedetects a current position of the vehicle, based on acquired position information of the vehicle, angle change information acquired from the gyro sensor, and vehicle speed acquired from the vehicle speed sensor.

13 20 The map databaseis a memory that stores three-dimensional high-definition map information including position information of various types of facilities and specific points and is configured to be accessible from the controller. The three-dimensional high-definition map information is three-dimensional map information based on road shapes detected when a vehicle for data acquisition traveled on actual roads. The three-dimensional high-definition map information is map information in which detailed and highly precise position information of a curved road and the amount of curvature (for example, curvature or radius of curvature) of the road, a junction of roads, a branch point, a tollgate, a point of reduction in the number of lanes, and the like is associated with map information as three-dimensional information.

14 1 The in-vehicle deviceis various types of devices mounted on the vehicleand operates in accordance with an operation by the passenger. Examples of such an in-vehicle device include a steering wheel, an accelerator pedal, a brake pedal, turn signals, windshield wipers, lights, a horn, other specific switches, and the like.

15 1 12 1 15 15 20 1 The navigation systemacquires or receives current position information of the vehiclefrom the positioning deviceand displays map information for navigation on which the position of the vehicleis superimposed on a display or the like. In addition, the navigation systemincludes a navigation function to, when a destination is set, set a route to the destination and guide the passenger along the set route. The navigation function displays a route on a map on the display and informs the passenger of the route by voice or the like. A route set by the navigation systemis also used in a route travel assistance function that the controllerincludes. The route travel assistance function is a function to cause the vehicleto autonomously travel to a destination, based on a set route.

16 15 16 20 The display deviceincludes, for example, a display that the navigation systemincludes, a display incorporated in a rearview mirror, a display incorporated in a meter section, a head-up display projected on a windshield, and the like. The display devicenotifies the passenger of various types of presented information in accordance with control by the controller.

17 15 17 20 The sound output deviceis a device to output acoustic information, such as a speaker that the navigation systemincludes, a speaker of an audio device, and a buzzer. The sound output devicenotifies the passenger of various types of presented information in accordance with control by the controller.

18 18 16 17 The input deviceis a device, such as a button switch that enables the passenger to input an operation by manual operation, a touch panel arranged on a display screen, and a microphone that enables the passenger to input an operation by voice. The passenger, by operating the input device, is able to input setting information in response to presented information presented by the display deviceand the sound output device.

2 FIG. 18 18 18 20 18 181 182 183 184 185 186 is a diagram illustrative of a portion of the input deviceof the present embodiment. The input devicemay be a button switch group that is arranged on, for example, a spoke of the steering wheel. The input deviceis used when turning on and off and the like of an autonomous travel control function that the controllerincludes are set. The input deviceincludes a main switch, a resume/accelerate switch, a set/coast switch, a cancel switch, an inter-vehicle distance adjustment switch, and a lane change assistance switch.

181 20 182 183 181 183 183 184 185 186 20 The main switchis a switch to turn on and off the autonomous travel control function of the controller. The resume/accelerate switchis a switch to, after the autonomous travel control function is turned off, set resumption of the autonomous travel control function at a set speed before the turning-off of the autonomous travel control function or to increase the set speed. The set/coast switchis a switch to start the autonomous travel control function. In order to start the autonomous travel control function, after the autonomous travel control function is turned on by the main switch, the set/coast switchis pressed. The set/coast switchis also a switch to decrease the set speed. The cancel switchis a switch to cancel the autonomous travel control function. The inter-vehicle distance adjustment switchis a switch to set an inter-vehicle distance to a preceding vehicle. The lane change assistance switchis a switch to, when the controllerconfirms start of a lane change to the passenger, instruct (accept) the start of the lane change.

2 FIG. 14 18 20 Note that, in addition to the button switch group illustrated in, a turn signal lever for the turn signals and a switch of another type of in-vehicle devicecan be used as the input device. For example, when the passenger operates the turn signal lever in the case where whether or not a lane change is performed in an automated manner is proposed by the controller, a lane change in a direction in which the turn signal lever is operated is performed instead of the proposed lane change.

19 1 1 19 1 1 19 The vehicle behavior control devicecontrols vehicle behavior of the vehicle. For example, when the vehicleperforms constant speed travel at a set speed by the autonomous travel control function, the vehicle behavior control devicecontrols operation of a drive mechanism and brake operation to achieve acceleration/deceleration and travel speed that enable the vehicleto travel at the set speed. In addition, when the vehicletravels following a preceding vehicle by the autonomous travel control function, the vehicle behavior control devicealso likewise controls the operation of the drive mechanism and the brake. Note that the operation control of the drive mechanism includes operation of an internal-combustion engine in the case of an engine-driven vehicle and operation of a motor for traveling in the case of an electric vehicle. In addition, the operation control of the drive mechanism includes torque distribution between an internal-combustion engine and a motor for traveling in the case of a hybrid vehicle.

19 19 1 In addition, when the vehicle behavior control deviceperforms lane-keeping control, a lane change assistance function, a passing assistance function, or a route travel assistance function, which will be described later, by the autonomous travel control function, the vehicle behavior control deviceperforms, in addition to the operation control of the drive mechanism and the brake, steering control of the vehicleby controlling operation of a steering actuator.

20 1 21 22 21 22 22 The controlleris one or a plurality of electronic control units (ECUs) for controlling travel of the vehicleand includes a processorand peripheral components, such as a storage device. The processormay be, for example, a central processing unit (CPU) or a micro-processing unit (MPU). The storage devicemay include a semiconductor storage device, a magnetic storage device, an optical storage device, and the like. The storage devicemay include registers, a cache memory, and a memory, such as a read only memory (ROM) and a random access memory (RAM), that are used as main storage devices.

20 21 22 Functions of the controller, which will be described below, are achieved by, for example, the processorexecuting computer programs stored in the storage device.

20 20 20 Note that the controllermay be formed using dedicated hardware for performing various types of information processing that will be described below. For example, the controllermay include a functional logic circuit that is implemented in a general-purpose semiconductor integrated circuit. For example, the controllermay include a programmable logic device (PLD), such as a field-programmable gate array (FPGA), and the like.

20 1 1 20 1 20 11 20 20 1 11 The controllerachieves a travel information acquisition function to acquire information relating to a travel state of the vehicleand an autonomous travel control function to autonomously control travel speed and/or steering of the vehicle. The travel information acquisition function of the controlleris a function to acquire travel information relating to a travel state of the vehicle. For example, the controllermay acquire, as the travel information, image information of the outside of the vehicle captured by the front view camera, the rear view camera, and the side view cameras in the sensor. In addition, the controlleracquires, as the travel information, detection results by the front radar, the rear radar, and the side radars. Further, the controlleralso acquires, as the travel information, vehicle speed information of the vehicledetected by the vehicle speed sensor in the sensorand image information of the face of the passenger captured by the in-vehicle camera.

20 1 12 20 15 20 13 20 14 14 Further, the controlleracquires, as the travel information, the current position information of the vehiclefrom the positioning device. In addition, the controlleracquires, as the travel information, a set destination and a route to the destination from the navigation system. Further, the controlleracquires, as the travel information, position information of a curved road and the amount of curvature (for example, curvature or radius of curvature) of the road, a junction of roads, a branch point, a tollgate, a point of reduction in the number of lanes, and the like from the map database. Moreover, the controlleracquires, as the travel information, information about operation of the in-vehicle deviceby the passenger from the in-vehicle device.

20 1 20 1 1 The autonomous travel control function of the controlleris a function to autonomously control travel of the vehiclewithout depending on operation by the passenger. The autonomous travel control function of the controllerinclude an autonomous speed control function to autonomously control travel speed of the vehicleand an autonomous steering control function to autonomously control steering of the vehicle. The autonomous speed control function and the autonomous steering control function of the present embodiment will be described below.

<Autonomous Speed Control Function>

1 1 1 11 13 The autonomous speed control function is a function to, when a preceding vehicle is detected, control the vehicleto travel following the preceding vehicle while performing inter-vehicle distance control in such a way as to keep an inter-vehicle distance matching vehicle speed with a vehicle speed set by the passenger as an upper limit. In contrast, when no preceding vehicle is detected, the autonomous speed control function controls the vehicleto perform constant speed travel at a vehicle speed set by the passenger. The former and the latter are also referred to as inter-vehicle distance control and constant speed control, respectively. Note that the autonomous speed control function may include a function to detect a speed limit of a road on which the vehicleis traveling from a road sign by the sensoror acquire a speed limit from the map information in the map databaseand automatically set the speed limit as a set vehicle speed.

11 1 19 The constant speed control is performed when it is detected by the front radar or the like in the sensorthat no preceding vehicle exists ahead in an own lane of the vehicle. In the constant speed control, the vehicle behavior control devicecontrols operation of the drive mechanism, such as the engine and the brake, in such a manner as to maintain a set traveling speed while feeding back vehicle speed data detected by the vehicle speed sensor.

11 1 19 The inter-vehicle distance control is performed when it is detected by the front radar or the like in the sensorthat a preceding vehicle exists ahead in the own lane of the vehicle. In the inter-vehicle distance control, the vehicle behavior control devicecontrols operation of the drive mechanism, such as the engine and the brake, in such a manner as to maintain a set inter-vehicle distance with a set travel speed as an upper limit while feeding back inter-vehicle distance data detected by the front radar.

<Autonomous Steering Control Function>

1 The autonomous steering control function is a function to perform the steering control of the vehicleby controlling operation of the steering actuator.

The autonomous steering control function includes, for example, the lane-keeping function, the lane change assistance function, the passing assistance function, and the route travel assistance function.

1 The lane-keeping function is a function to assist steering of the passenger by controlling the steering actuator in such a way that, for example, the vehicletravels along substantially the center of a lane.

183 181 20 20 20 When the set/coast switchis pressed after the autonomous travel control function is turned on by the main switch, the controllerdetermines whether or not a predetermined autonomous travel control start condition is established. When the controllerdetermines that the autonomous travel control start condition is established, the controllerperforms the lane-keeping function in the autonomous steering control function.

181 20 183 183 20 Alternatively, when the autonomous travel control start condition is established after the autonomous travel control function is turned on by the main switch, the controllerwaits for the set/coast switchto be pressed. When the set/coast switchis pressed, the controllerstarts the autonomous travel control and performs the lane-keeping function in the autonomous steering control function.

<Lane Change Assistance Function>

The lane change assistance function starts lane change operation that is a series of processing for automated lane change when the passenger operates the turn signal lever to turn on a turn signal and a predetermined lane change start condition is satisfied. The lane change assistance function determines whether or not the predetermined lane change start condition is established, based on various types of travel information acquired by the travel information acquisition function.

1 The lane change assistance function starts the lane change operation when the lane change start condition is satisfied. The lane change operation causes the vehicleto laterally move to an adjacent lane and, when the movement to the adjacent lane is finished, turns off the turn signal and starts performance of the lane-keeping function in the adjacent lane.

<Passing Assistance Function>

1 1 16 186 18 When a preceding vehicle that is slower than the vehicleexists ahead in the own lane of the vehicleand a predetermined passing proposition condition is satisfied, the passing assistance function presents passing information to the passenger by the display device. In this configuration, the passing information is information for proposing passing the preceding vehicle to the passenger. The passing assistance function turns on a turn signal and starts the above-described lane change operation when the passenger accepts the passing by operating the lane change assistance switchin the input devicein response to the presentation of the passing information and a preset passing start condition is satisfied. The passing assistance function determines whether or not the passing proposition condition and the passing start condition are established, based on various types of travel information acquired by the travel information acquisition function.

<Route Travel Assistance Function>

16 186 When a travel direction change point, such as a branch point, a junction, an exit, and a tollgate, exists in a set route, distance to the travel direction change point is within a predetermined distance, and a predetermined route travel proposition condition is satisfied, the route travel assistance function presents route travel information by the display deviceand proposes a lane change toward the travel direction change point. In addition, the route travel assistance function starts lane change operation when the proposition of lane change is accepted by an operation of the lane change assistance switchand a predetermined route travel start condition is satisfied.

The route travel assistance function determines whether or not the route travel proposition condition and the route travel start condition are established, based on various types of travel information acquired by the travel information acquisition function.

1 1 1 1 In the route travel assistance function, there are some cases where when a road on which the vehicleis traveling includes three or more lanes, multiple lane changes are successively performed. When a travel lane of the vehiclebefore a lane change is proposed is referred to as “own lane”, there is a case where the vehicleperforms a first lane change from the own lane to an adjacent lane of the own lane and performs a second lane change from the adjacent lane to further adjacent lane on the opposite side of the adjacent lane to the own lane. Hereinafter, a final destination lane of lane changes to which the vehicleis caused to perform the lane changes by the route travel assistance function is referred to as “target lane”.

When, in the route travel assistance function, multiple lane changes to be successively performed (hereinafter, simply referred to as “multiple lane changes”) are proposed, the passenger can select, as a method for accepting lane changes, a “collective acceptance mode” or an “individual acceptance mode”.

20 186 20 In the collective acceptance mode, the passenger collectively accepts multiple lane changes. The controllercollectively proposes multiple lane changes before performing a lane change from the own lane to an adjacent lane that is the first lane change included in the multiple lane changes. When the passenger accepts the lane changes by operating the lane change assistance switch, the controller, without proposing the second or later lane changes included in the multiple lane changes, performs all lane changes included in the multiple lane changes.

20 186 In the individual acceptance mode, the passenger individually accepts each lane change included in the multiple lane changes. The controllerproposes a lane change every time before starting each lane change included in the multiple lane changes. The passenger accepts each lane change by operating the lane change assistance switch.

15 For example, the passenger can set which of the “collective acceptance mode” and the “individual acceptance mode” is to be selected by operating the navigation system.

16 When the route travel assistance function proposes a lane change, the route travel assistance function displays a lane change image that represents a course of a lane change to be proposed on the display device.

3 FIG. 16 161 161 161 161 161 161 161 a a b c a c illustrates an example of a lane change image when a lane change is proposed in the collective acceptance mode. The display devicemay display a lane change imagein a meter section in front of a driver seat. For example, the lane change imagemay be displayed between a speedometer and a tachometer in the meter section. The same applies to lane change imagesand, which will be described later. The lane change imagestoare collectively referred to as “lane change image”.

161 162 1 162 163 163 162 161 162 162 163 163 161 a b a b 3 FIG. The lane change imageincludes a road image that represents an own lanethat is a lane in which the vehicleis currently traveling and one or more other lanes existing on at least one lateral side of the own laneand including at least adjacent lanesandthat are adjacent to the own lane. Other lanes displayed in the lane change imageare lanes other than the own lanethat have the same travel directions as the own laneand, in the example in, include only the adjacent lanesand. In the following description, other lanes that are currently displayed in the lane change imageare referred to as “displayed other lanes”.

1 163 163 162 161 a a Note that when, for example, the vehicle, by performing a lane change to the right side, starts traveling in a lane having been displayed as the adjacent lane, a lane having been displayed as the adjacent lanebefore the lane change is displayed as the own lanein the lane change images.

163 161 163 a a In addition, when an adjacent lane exists further on the right side of the lane having been displayed as the adjacent lanebefore the lane change, such an adjacent lane, although not having been displayed in the lane change imagebefore the lane change, comes to be displayed as the adjacent lane(that is, as a displayed other lane) after the lane change.

161 Note that the lane change imagerepresenting a course of a lane change is displayed only in the route travel assistance function and do not have to be displayed in other functions involving a lane change, for example, the lane change assistance function and the passing assistance function.

3 FIG. 3 FIG. 161 1 162 163 161 164 162 163 a a a a a illustrates an example of the lane change imagein the case where a target lane that is a destination lane of a lane change to which the vehicleis caused to perform a lane change is not a lane on the outer side of the displayed other lanes as viewed from the own lane, that is, in the case where the target lane is one of the displayed other lanes. In the example in, the target lane is the adjacent lane. In such a case, in the lane change image, a course displayrepresenting a course in which a lane change from the own laneto the target laneincluded in the displayed other lanes is performed is superimposed on the road image.

164 1 162 a 3 FIG. The course displaymay be a belt-shaped display in which a range on the road surface that the vehiclepasses at the time of lane change is schematically displayed as illustrated in, for example,or a display of an arrow that extends from the own laneto the target lane.

161 165 1 165 1 In the lane change image, an iconof the vehiclemay be superimpose on the road image. The iconof the vehiclemay be omitted according to the settings.

161 166 In addition, in the lane change imagedisplayed while a lane change is proposed (that is, before start of a lane change), a course displayin the case of not performing a lane change may be superimposed on the road image.

161 a Hereinafter, the lane change imagethat is displayed when the target lane is not a lane on the outer side of the displayed other lanes in the collective acceptance mode is sometimes referred to as “first lane change image”.

4 FIG. 4 FIG. 161 162 162 162 b illustrates an example of the lane change imagethat is displayed when the target lane is a lane on the outer side of the displayed other lanes as viewed from the own lane(that is, when the target lane is none of the displayed other lanes). In the example in, the target lane is the fifth next lane from the own laneon the right side of the own lane.

161 164 162 163 164 1 162 b b a b 4 FIG. 4 FIG. In such a case, in the lane change image, a course displayrepresenting a course in which a lane change from the own laneto one of the displayed other lanes (in the case of, the adjacent lane) is performed and a lane change to the outer side of the displayed other lanes is further performed is superimposed on the road image. The course displaymay be a belt-shaped display in which a range on the road surface that the vehiclepasses at the time of lane change is schematically displayed as illustrated in, for example,or a display of an arrow that starts from the own lane, passes the displayed other lanes, and extends to the outer side of the displayed other lanes.

167 161 b. In addition, when the number of lane changes that have not been performed (the number of remaining lane changes) among lane changes proposed by the route travel assistance function is two or more, a numeralindicating the number of remaining lane changes may be displayed in the lane change image

161 b Hereinafter, the lane change imagethat is displayed when the target lane is a lane on the outer side of the displayed other lanes in the collective acceptance mode is sometimes referred to as “second lane change image”.

161 161 b b 3 4 FIGS.and The number of lanes displayed in the lane change imageis not limited to three as in the examples in. The number of lanes displayed in the lane change imagemay be, for example, two, and the lanes may be a plurality of lanes the number of which is four or more.

5 FIG. 161 161 163 163 163 163 163 163 163 163 b b a d a b c d a b illustrates an example of a second lane change imagein the case where the number of lanes displayed in the lane change imageis five. In this case, as displayed other lanesto, the adjacent lanesandand further adjacent lanesandof the adjacent lanesandare displayed.

1 163 163 162 163 163 c d c d Therefore, when the target lane that is a destination lane of a lane change to which the vehicleis caused to perform a lane change is the laneordescribed above, a first lane change image (not illustrated) in which a course display representing a course in which lane changes from the own laneto the target laneorare performed is superimposed on the road image is displayed.

6 FIG. 4 FIG. 161 161 161 166 b b b is a diagram illustrative of an example of a second lane change imageat a time point at which, after the second lane change imageinis displayed and a lane change is proposed, the lane change is started. When a lane change by the route travel assistance function is started by the passenger accepting the lane change, the second lane change imagechanges to an image in which the course displayin the case where the lane change is not performed is not displayed.

1 162 1 162 Subsequently, when the lane change is performed, the lane change image is updated in such a way that a lane in which the vehicletravels after the lane change is displayed as the own lane. On this occasion, when multiple lane changes are performed, the lane change image is switched every time a single lane change is performed in such a way that a lane in which the vehicletravels after the lane change is displayed as the own lanein turn.

7 FIG. 7 FIG. 7 FIG. 6 FIG. 20 16 161 161 161 163 b a b a. When the lane change image is switched every time a single lane change is performed as described above and the number of remaining lane changes among the lane changes proposed by the route travel assistance function becomes one, the lane change image changes to an image illustrated in. That is, when the lane change image is updated and the target lane becomes not a lane on the outer side of the displayed other lanes, the controllerchanges the lane change image to be displayed on the display devicefrom the second lane change imageto a first lane change imageas illustrated in. In the example in, by four lane changes being performed after the second lane change imageinis displayed, the target lane is displayed as an adjacent lane

8 FIG. 162 161 162 163 161 161 164 162 c a c c c illustrates an example of a lane change image when a lane change is proposed in the individual acceptance mode. In the individual acceptance mode, regardless of whether or not the target lane is a lane on the outer side of the displayed other lanes as viewed from the own lane, a lane change imagein which a course display representing a course in which a lane change from the own laneto the adjacent laneis performed is superimposed on the road image is displayed. The lane change imagedisplayed in the individual acceptance mode is sometimes referred to as “third lane change image”. In the lane change image, a course displayrepresenting a course in which a lane change from the own laneto an adjacent lane is performed is superimposed on the road image.

161 167 167 161 c c. 8 FIG. 3 7 FIGS.to Although, in the example of the third lane change imagein, the numeral(see) indicating the number of lane changes that have not been performed (the number of remaining lane changes) among lane changes proposed by the route travel assistance function is not displayed, such a numeralmay be displayed in the third lane change image

(Operation)

9 FIG. 10 is a flowchart illustrative of an example of operation of the driving assistance deviceof the embodiment.

1 15 1 In step S, the navigation systemcalculates a route from the current position of the vehicleto a destination.

2 20 1 1 2 3 1 2 7 In step S, the controller, while performing the route travel assistance function, determines whether or not the vehiclehas reached a point at a predetermined distance to a travel direction change point, such as a branch point, existing on the route. When the vehiclehas reached a point at a predetermined distance to a travel direction change point (step S: Y), the process proceeds to step S. When the vehiclehas not reached a point at a predetermined distance to a travel direction change point (step S: N), the process proceeds to step S.

3 20 1 In step S, the controllerdetermines a target lane of a lane change, based on the route calculated in step S.

4 20 4 5 4 6 In step S, the controllerdetermines whether an acceptance method of a lane change is set to the collective acceptance mode or the individual acceptance mode. When the acceptance method is set to the collective acceptance mode (step S: Y), the process proceeds to step S. When the acceptance method is set to the individual acceptance mode (step S: N), the process proceeds to step S.

5 20 7 10 FIG. In step S, the controllerperforms collective lane change processing. The collective lane change processing will be described later with reference to. Subsequently, the process proceeds to step S.

6 20 7 11 FIG. In step S, the controllerperforms individual lane change processing. The individual lane change processing will be described later with reference to. Subsequently, the process proceeds to step S.

7 20 1 7 2 7 In step S, the controllerdetermines whether or not an ignition key of the vehicleis turned off. When the ignition key has not been turned off (step S: N), the process returns to step S. When the ignition key is turned off (step S: Y), the process terminates.

10 FIG. Next, an example of the collective lane change processing will be described with reference to.

10 20 10 11 10 12 In step S, the controllerdetermines whether or not the target lane is a lane on the outer side of displayed other lanes as viewed from an own lane. When the target lane is not a lane on the outer side of the displayed other lanes (step S: N), the process proceeds to step S. When the target lane is a lane on the outer side of the displayed other lanes (step S: Y), the process proceeds to step S.

11 20 161 16 13 a In step S, the controllerdisplays a first lane change imageon the display deviceand proposes a lane change to the target lane. Subsequently, the process proceeds to step S.

12 20 161 16 13 b In step S, the controllerdisplays a second lane change imageon the display deviceand proposes a lane change to the target lane. Subsequently, the process proceeds to step S.

13 20 13 14 13 20 In step S, the controllerdetermines whether or not the proposed lane change is accepted by a passenger. When the lane change is accepted (step S: Y), the process proceeds to step S. When the lane change is not accepted (step S: N), the controllerterminates the collective lane change processing.

14 20 1 In step S, the controllerperforms a single lane change from the own lane in which the vehicleis currently traveling to an adjacent lane.

15 20 1 15 20 In step S, the controllerdetermines whether or not all lane changes are finished (that is, whether or not the vehiclehas reached the target lane). When all the lane changes are finished (step S: Y), the controllerterminates the collective lane change processing.

15 16 161 1 162 When all the lane changes have not been finished (step S: N), the process proceeds to step Sin order to update the lane change imageand display a travel lane of the vehicleafter lane change as the own lane.

16 20 16 17 16 18 In step S, the controllerdetermines whether or not the target lane is a lane on the outer side of the displayed other lanes as viewed from the own lane. When the target lane is not a lane on the outer side of the displayed other lanes (step S: N), the process proceeds to step S. When the target lane is a lane on the outer side of the displayed other lanes (step S: Y), the process proceeds to step S.

17 20 161 16 14 a In step S, the controllerdisplays a first lane change imageon the display device. Subsequently, the process returns to step S.

18 20 161 16 14 b In step S, the controllerdisplays a second lane change imageon the display device. Subsequently, the process returns to step S.

11 FIG. Next, an example of the individual lane change processing will be described with reference to.

20 20 161 16 c In step S, the controllerdisplays a third lane change imageon the display deviceand proposes a lane change to an adjacent lane.

21 20 21 22 21 20 In step S, the controllerdetermines whether or not the received proposed lane change is accepted by the passenger. When the lane change is accepted (step S: Y), the process proceeds to step S. When the lane change is not accepted (step S: N), the controllerterminates the individual lane change processing.

22 20 1 In step S, the controllerperforms a single lane change from the own lane in which the vehicleis currently traveling to the adjacent lane.

23 20 1 23 20 161 1 162 23 20 c In step S, the controllerdetermines whether or not all lane changes are finished (that is, whether or not the vehiclehas reached the target lane). When all the lane changes have not been finished (step S: N), the process proceeds to step Sin order to update the lane change imageand display a travel lane of the vehicleafter lane change as the own lane. When all the lane changes are finished (step S: Y), the controllerterminates the individual lane change processing.

20 1 1 16 (1) The controllerexecutes processing including: generating a road image representing an own lane that is a lane in which the vehicletravels and one or more other lanes existing on at least one lateral side of the own lane and including at least an adjacent lane that is adjacent to the own lane; generating a lane change image by, in the case where when the vehicleis caused to perform a lane change by the autonomous travel control, a target lane that is a destination lane of the lane change is determined to be one of displayed other lanes that are the other lanes displayed in the road image, superimposing a first course display representing a course in which a lane change from the own lane to the target lane included in the displayed other lanes is performed on the road image and, in the case where the target lane is determined to be none of the displayed other lanes, superimposing a second course display representing a course in which a lane change from the own lane to one of the displayed other lanes is performed and a lane change to the outer side of the displayed other lane is further performed on the road image; and displaying the lane change image on the display device.

1 16 Because of this configuration, when the vehicleis caused to perform a lane change by the autonomous travel control, it is possible to, before the lane change is started, inform the passenger of whether a lane change to one of the displayed other lanes (for example, an adjacent lane) displayed on the display deviceis to be performed or another lane change further continues.

10 16 1 16 16 20 1 1 (2) The controllermay determine a target lane, based on a target route (route) from the current position of the vehicleto a destination. This configuration enables a lane change for causing the vehicleto travel along the target route. 20 (3) The lane change to a target lane may include multiple lane changes that are successively performed, and the first lane change included in the multiple lane changes may be a lane change from the own lane to an adjacent lane. The controllermay display a lane change image before the first lane change is performed. Because of this configuration, it is possible to, before the first lane change is performed, present whether, by multiple lane changes that are successively performed, a lane change to one of the displayed other lanes is performed or a lane change to the outer side of the displayed other lanes is performed to the passenger. 15 20 (4) The navigation systemor the controllermay store a setting by the passenger for selecting one of the collective acceptance mode in which multiple lane changes are collectively accepted and the individual acceptance mode in which multiple lane changes are individually accepted. The display device in JP 2018-079202 A described above can display only a lane change from the own lane to an adjacent lane even when multiple lane changes are successively performed. In contrast, the driving assistance deviceof the embodiment is capable of displaying, on the display device, whether, by a lane change performed by the autonomous travel control, the vehicleperforms a lane change to one of the displayed other lanes displayed on the display deviceor performs a lane change to the outer side of the displayed other lanes. That is, it is possible to cause details of control performed by the autonomous travel control and a display on the display deviceto coincide with each other. Because of this capability, presentation of information relating to the autonomous travel control to the passenger can be improved.

20 The controllermay, when the collective acceptance mode is set, display a lane change image on which the first course display or the second course display is superimposed and, when the individual acceptance mode is set, before the first lane change is performed, display a lane change image in which a third course display representing a course in which a lane change from the own lane to an adjacent lane is performed is superimposed on the road image.

16 20 (5) The controllermay display a numeral indicating the number of remaining lane changes among multiple lane changes in the lane change image. Because of this configuration, even when the target lane is a lane on the outer side of the displayed other lanes as viewed from the own lane, it is possible to present how may lane changes are to be performed to the passenger. 20 (6) When a lane change is performed after a lane change image in which the second course display is superimposed on the road image is displayed and the target lane becomes one of the displayed other lanes, the controllermay display a lane change image in which the first course display is superimposed on the road image. Because of this configuration, it is possible to change the lane change image according to progress of lane changes. Because of this configuration, it is possible to cause a range of lane change that are performed based on a single acceptance action (that is, a range of control that the autonomous travel control performs based on a single acceptance action) and a display on the display deviceto coincide with each other according to which of the collective acceptance mode and the individual acceptance mode is set. Because of this capability, presentation of information relating to the autonomous travel control to the passenger can be improved.

All examples and conditional language provided herein are intended for the pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although one or more embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.

1 Vehicle 10 Driving assistance device 11 Sensor 12 Positioning device 13 Map database 14 In-vehicle device 15 Navigation system 16 Display device 17 Sound output device 18 Input device 19 Vehicle behavior control device 20 Controller 21 Processor 22 Storage device